外科休克(surgical+shock)_PPT幻灯片

• A breakdown of effective circulation • Inadequate tissue perfusion • Decreased oxygen supply • Anaerobic metabolism • Accumulation of metabolic waste • Multiple organ failure • A clinical syndrome
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Pathophysiology
1. Microcirculatory changes 2. The changes of body fluid metabolism 3. Mediators of inflammasion injury 4. Secondary lesion
fluid and no perfusion
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Compensatory significance
Keeping blood pressure Perfusion to vital organs normal
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Clinical manifestation of Shock
Early Stage (compensated shock):
Heart Rate: moderate tachycardia; weak and thready pulse Level of Consciousness: confusion or unconsciousness Skin: delayed capillary refill; cold, clammy, and cyanotic Blood Pressure: decreased Respirations: rapid and shallow Urine output: oliguria
• A history of the 200 years to recognize shock:
“shake”, “attack” From superficial syndrome to microcirculatory level ,
cellular level, molecular level
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Types of Shock
• Hypovolemic Shock: – haemorrhagic – traumatic – dehydration
• Other causes of shock – Septic Shock – Cardiogenic Shock – Neurogenic Shock – Hypersensitive Shock
plasma shift to interstitual spaces pachyemia and increasing blood viscidity
perfusion and no fluid
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Middle Stage (uncompensated shock): Compensatory mechanisms are unable to maintain perfusion
Objectives
• Understand what is shock ？ • Define types of shock • Understand pathophysiology of shock • Understand how to treat shock
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Development of the concept of shock
Skin:
delayed capillary refill; cool and clammy
Blood Pressure:
normal or slightly elevated
Respirations:
rapid and shallow
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Compensatory mechanisms （ Progressive shock）
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Compensatory mechanisms (early shock)
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Compensatory mechanisms
precapillary resistance vessel to contract， to decrease capilary hydrostatic pressure.
arteriovenous shunt, direct passage way to open tissue hypoperfusion
anaerobic metabolism lactic acid builds up metabolic acidosis
Pre- CRV to dilate Post- CRV to contract capillary hydrostatic pressure to increase
Compensatory mechanisms are able to maintain perfusion of vital organs
Heart Rate:
mild tachycardia; bounding pulse
Level of Consciousness: lethargy, confusion, combativeness
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WHAT IS SHOCK?
Shock results from poor tissue perfusion and tissue hypoxia from inadequate circulatory compensations needed to sustain acutely increased body metabolism.
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1. Microcirculation
• Precapillary resistance vessel： arteriole、metarteriole、precapillary sphincter
• Postcapillary resistance vessel：veinule • Microcirculation perfusion：
• Circulatory level： blood pressure • Microcirculatory level： inadequate tissue perfusion • Cellular level and molecular level：
Frontier Exploratory stage，experimental therapies